An efficient and convenient protocol for the synthesis of 2H-chromenones has been developed. In the presence of tBuOK in DMF, good to excellent yields of various chromenones were obtained from the corresponding salicylaldehydes and arylacetonitriles. No protection of inert gas atmosphere is required here.

Using a new photochemical model of the Earth’s early atmosphere, the relationship between noble gas photoionization and organic photochemistry has been investigated from the Archean eon to the present day. We have found that the enhanced UV emission of the young Sun triggered a peculiar atmospheric chemistry in a CH4-rich early atmosphere that resulted in the increased formation of an organic h...

We study numerically low-order harmonic generation in noble gases pumped by intense femtosecond laser pulses in the tunneling ionization regime. We analyze the influence of the phase-mismatching on this process, caused by the generated plasma, and study in dependence on the pump intensity the origin of harmonic generation arising either from the bound-electron nonlinearity or the tunnel-ionizat...

7-fs-pulses with 0.3 mJ are obtained after filamentation in argon and compression by double-chirped-mirrors. These pulses are used to generate high-order harmonics in a semi-infinite gas cell in different noble gases. Spectral broadening of high-order harmonics in xenon and argon is observed. In neon, an extended continuous cut-off region down to 10 nm (124 eV) is observed which is to the best ...

Gaseous supersaturation can be induced under steady-state conditions when two inert gases are transmitted in opposite directions across any system comprising a diffusion barrier adjacent to a zone of limited convective capacity. This has many implications for bubble formation in vivo and can explain the occurence of symptoms of decompression sickness without decompression.

Molecular dynamics data are reported for two-body and three-body interactions in noble gases at densities covering the gas, liquid, and solid phases. The data indicate that simple relationships exist between three- and two-body interactions in both fluid and solid phases. The relationship for liquids has a simple density dependence with only one external parameter. In contrast, the solid phase ...

The Galileo probe showed that Jupiter's atmosphere is severely depleted in neon compared to protosolar values. We show via ab initio simulations of the partitioning of neon between hydrogen-helium phases that the observed depletion can be explained by the sequestration of neon into helium-rich droplets within the postulated hydrogen-helium immiscibility layer of the planets interior. We also de...

The reaction of [LWCl] (3) [L = N(CH2CH2NiPr)3] with LiE(SiMe3)2 (E = P, As, Sb) yields the novel, neutral pnictido-bridged complexes [LW = E = WL] (5-7). By following the reaction, which starts from the LiP-(SiMe3)2 derivative, by 31P NMR spectroscopy, the formation of an intermediate with a terminal pnictido ligand can be ruled out. The paramagnetic complexes 5-7 are comprehensively spectrosc...